Method for transmitting and receiving signal by terminal in wireless communication system and apparatus therefor

ABSTRACT

The present invention relates to a method and an apparatus for transmitting and receiving a signal by a terminal in a wireless communication system supporting reconfiguration of wireless resources. Specifically, the method comprises a step of monitoring wireless resource reconfiguration control information on a number of sub-frames within a set monitoring cycle in order to reconfigure wireless resources, wherein a first uplink-downlink setting in accordance with wireless resource reconfiguration control information is valid only if equally detected on a number of sub-frames, and wherein a number of sub-frames are sub-frames set to monitor wireless resource reconfiguration control information of a terminal.

TECHNICAL FIELD

The present invention relates to a wireless communication system, andmore particularly, to a method of transmitting and receiving a signal ofa user equipment in a wireless communication system and apparatustherefor.

BACKGROUND ART

A 3rd generation partnership project long term evolution (3GPP LTE)(hereinafter, referred to as ‘LTE’) communication system which is anexample of a wireless communication system to which the presentinvention can be applied will be described in brief.

FIG. 1 is a diagram illustrating a network structure of an EvolvedUniversal Mobile Telecommunications System (E-UMTS) which is an exampleof a wireless communication system. The E-UMTS is an evolved version ofthe conventional UMTS, and its basic standardization is in progressunder the 3rd Generation Partnership Project (3GPP). The E-UMTS may bereferred to as a Long Term Evolution (LTE) system. Details of thetechnical specifications of the UMTS and E-UMTS may be understood withreference to Release 7 and Release 8 of “3rd Generation PartnershipProject; Technical Specification Group Radio Access Network”.

Referring to FIG. 1, the E-UMTS includes a User Equipment (UE), basestations (eNode B; eNB), and an Access Gateway (AG) which is located atan end of a network (E-UTRAN) and connected to an external network. Thebase stations may simultaneously transmit multiple data streams for abroadcast service, a multicast service and/or a unicast service.

One or more cells exist for one base station. One cell is set to one ofbandwidths of 1.44, 3, 5, 10, 15 and 20 MHz to provide a downlink oruplink transport service to several user equipments. Different cells maybe set to provide different bandwidths. Also, one base station controlsdata transmission and reception for a plurality of user equipments. Thebase station transmits downlink (DL) scheduling information of downlinkdata to the corresponding user equipment to notify the correspondinguser equipment of time and frequency domains to which data will betransmitted and information related to encoding, data size, and hybridautomatic repeat and request (HARQ). Also, the base station transmitsuplink (UL) scheduling information of uplink data to the correspondinguser equipment to notify the corresponding user equipment of time andfrequency domains that can be used by the corresponding user equipment,and information related to encoding, data size, and HARQ. An interfacefor transmitting user traffic or control traffic may be used between thebase stations. A Core Network (CN) may include the AG and a network nodeor the like for user registration of the user equipment. The AG managesmobility of the user equipment on a Tracking Area (TA) basis, whereinone TA includes a plurality of cells.

Although the wireless communication technology developed based on WCDMAhas been evolved into LTE, request and expectation of users andproviders have continued to increase. Also, since another wirelessaccess technology is being continuously developed, new evolution of thewireless communication technology will be required for competitivenessin the future. In this respect, reduction of cost per bit, increase ofavailable service, use of adaptable frequency band, simple structure andopen type interface, proper power consumption of the user equipment,etc. are required.

A terminal periodically and/or aperiodically reports information on acurrent channel state to a base station to assist efficient managementof a wireless communication system of the base station. Since theinformation on the channel state reported to the base station is able toinclude results calculated in consideration of various situations, amore efficient reporting method is required.

DISCLOSURE OF THE INVENTION Technical Task

Based on the above-mentioned discussions, the technical task of thepresent invention is to propose a method of transmitting and receiving asignal of a user equipment in a wireless communication system andapparatus therefor.

Technical tasks obtainable from the present invention are non-limited bythe above-mentioned technical task. And, other unmentioned technicaltasks can be clearly understood from the following description by thosehaving ordinary skill in the technical field to which the presentinvention pertains.

Technical Solutions

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amethod of transmitting and receiving a signal in a user equipment of awireless communication system supportive of reconfiguration of radioresource according to one embodiment of the present invention mayinclude the step of monitoring a radio resource reconfiguration controlinformation on a multitude of subframes in monitoring periodicity setfor radio resource reconfiguration, wherein a first UL-DL configurationaccording to the radio resource reconfiguration control information isvalid only if detected equally from a multitude of the subframes andwherein a multitude of the subframes comprise subframes configured tomonitor the radio resource reconfiguration control information of theuser equipment.

The method may further include the step of if the first UL-DLconfiguration is not valid, performing fallback for transceiving thesignal with a base station according to a second UL-DL configuration onSIB (system information block).

The method may further include the step of if the first UL-DLconfiguration is valid, transceiving the signal with the base station ona time interval having the first UL-DL configuration applied thereto.

The radio resource reconfiguration information may be transmittedthrough common search space (CSS) on downlink control channel (physicaldownlink control channel (PDCCH)). The first UL-DL configuration may beindicated using an indicator included in the radio resourcereconfiguration control information. The radio resource reconfigurationcontrol information may include a multitude of indicators and whereinthe first UL-DL configuration is indicated according to an indicatorcorresponding to a field designated to be monitored by the userequipment among a multitude of the indicators.

And, a multitude of the subframes may be indicated by an upper layer.

In another aspect of the present invention, as embodied and broadlydescribed herein, in transceiving a signal in a wireless communicationsystem supportive of reconfiguration of radio resource, a user equipmentaccording to another embodiment of the present invention may include aradio frequency unit and a processor configured to monitor a radioresource reconfiguration control information on a multitude of subframesin monitoring periodicity set for radio resource reconfiguration,wherein a first UL-DL configuration according to the radio resourcereconfiguration control information is valid only if detected equallyfrom a multitude of the subframes and wherein a multitude of thesubframes comprise subframes configured to monitor the radio resourcereconfiguration control information of the user equipment.

Advantageous Effects

According to the present invention, signal transmission and receptioncan be efficiently performed in a wireless communication system.

Effects obtainable from the present invention are non-limited by theabove mentioned effect. And, other unmentioned effects can be clearlyunderstood from the following description by those having ordinary skillin the technical field to which the present invention pertains.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

FIG. 1 shows a structure of E-UMTS network as one example of a wirelesscommunication system.

FIG. 2 shows structures of a control plane and a user plane of a radiointerface protocol between a user equipment and E-UTRAN based on 3GPPradio access network specifications.

FIG. 3 shows physical channels used in 3GPP LTE system and a generalsignal transmitting method using the same.

FIG. 4 shows a configuration of a radio frame used in LTE system.

FIG. 5 shows a resource grid for a downlink slot.

FIG. 6 shows a configuration of a downlink subframe.

FIG. 7 shows a resource unit used in configuring a downlink controlchannel in LTE system.

FIG. 8 shows one example of a carrier aggregation (CA) communicationsystem.

FIG. 9 shows one example of a scheduling in case of aggregating aplurality of carriers.

FIG. 10 shows one example of EPDCCH and PDSCH scheduled by EPDCCH.

FIG. 11 shows one example of performing CoMP.

FIG. 12 shows a case that usage of radio resource is dynamically changedin TDD system environment.

FIG. 13 shows a base station and a user equipment applicable to oneembodiment of the present invention.

BEST MODE FOR INVENTION

The following technology may be used for various wireless accesstechnologies such as CDMA (code division multiple access), FDMA(frequency division multiple access), TDMA (time division multipleaccess), OFDMA (orthogonal frequency division multiple access), andSC-FDMA (single carrier frequency division multiple access). The CDMAmay be implemented by the radio technology such as UTRA (universalterrestrial radio access) or CDMA2000. The TDMA may be implemented bythe radio technology such as global system for mobile communications(GSM)/general packet radio service (GPRS)/enhanced data rates for GSMevolution (EDGE). The OFDMA may be implemented by the radio technologysuch as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, andevolved UTRA (E-UTRA). The UTRA is a part of a universal mobiletelecommunications system (UMTS). A 3rd generation partnership projectlong term evolution (3GPP LTE) is a part of an evolved UMTS (E-UMTS)that uses E-UTRA, and adopts OFDMA in a downlink and SC-FDMA in anuplink. LTE-advanced (LTE-A) is an evolved version of the 3GPP LTE.

For clarification of the description, although the following embodimentswill be described based on the 3GPP LTE/LTE-A, it is to be understoodthat the technical spirits of the present invention are not limited tothe 3GPP LTE/LTE-A. Also, specific terminologies hereinafter used in theembodiments of the present invention are provided to assistunderstanding of the present invention, and various modifications may bemade in the specific terminologies within the range that they do notdepart from technical spirits of the present invention.

FIG. 2 is a diagram illustrating structures of a control plane and auser plane of a radio interface protocol between a user equipment andE-UTRAN based on the 3GPP radio access network standard. The controlplane means a passageway where control messages are transmitted, whereinthe control messages are used by the user equipment and the network tomanage call. The user plane means a passageway where data generated inan application layer, for example, voice data or Internet packet dataare transmitted.

A physical layer as the first layer provides an information transferservice to an upper layer using a physical channel. The physical layeris connected to a medium access control (MAC) layer via a transportchannel, wherein the medium access control layer is located above thephysical layer. Data are transferred between the medium access controllayer and the physical layer via the transport channel. Data aretransferred between one physical layer of a transmitting side and theother physical layer of a receiving side via the physical channel. Thephysical channel uses time and frequency as radio resources. In moredetail, the physical channel is modulated in accordance with anorthogonal frequency division multiple access (OFDMA) scheme in adownlink, and is modulated in accordance with a single carrier frequencydivision multiple access (SC-FDMA) scheme in an uplink.

A medium access control (MAC) layer of the second layer provides aservice to a radio link control (RLC) layer above the MAC layer via alogical channel. The RLC layer of the second layer supports reliabledata transmission. The RLC layer may be implemented as a functionalblock inside the MAC layer. In order to effectively transmit data usingIP packets such as IPv4 or IPv6 within a radio interface having a narrowbandwidth, a packet data convergence protocol (PDCP) layer of the secondlayer performs header compression to reduce the size of unnecessarycontrol information.

A radio resource control (RRC) layer located on the lowest part of thethird layer is defined in the control plane only. The RRC layer isassociated with configuration, re-configuration and release of radiobearers (‘RBs’) to be in charge of controlling the logical, transportand physical channels. In this case, the RB means a service provided bythe second layer for the data transfer between the user equipment andthe network. To this end, the RRC layers of the user equipment and thenetwork exchange RRC message with each other. If the RRC layer of theuser equipment is RRC connected with the RRC layer of the network, theuser equipment is in an RRC connected mode. If not so, the userequipment is in an RRC idle mode. A non-access stratum (NAS) layerlocated above the RRC layer performs functions such as sessionmanagement and mobility management.

One cell constituting a base station eNB is set to one of bandwidths of1.4, 3.5, 5, 10, 15, and 20 MHz and provides a downlink or uplinktransmission service to several user equipments. At this time, differentcells may be set to provide different bandwidths.

As downlink transport channels carrying data from the network to theuser equipment, there are provided a broadcast channel (BCH) carryingsystem information, a paging channel (PCH) carrying paging message, anda downlink shared channel (SCH) carrying user traffic or controlmessages. Traffic or control messages of a downlink multicast orbroadcast service may be transmitted via the downlink SCH or anadditional downlink multicast channel (MCH). Meanwhile, as uplinktransport channels carrying data from the user equipment to the network,there are provided a random access channel (RACH) carrying an initialcontrol message and an uplink shared channel (UL-SCH) carrying usertraffic or control message. As logical channels located above thetransport channels and mapped with the transport channels, there areprovided a broadcast control channel (BCCH), a paging control channel(PCCH), a common control channel (CCCH), a multicast control channel(MCCH), and a multicast traffic channel (MTCH).

FIG. 3 is a diagram illustrating physical channels used in a 3GPP LTEsystem and a general method for transmitting a signal using the physicalchannels.

The user equipment performs initial cell search such as synchronizingwith the base station when it newly enters a cell or the power is turnedon at step S301. To this end, the user equipment synchronizes with thebase station by receiving a primary synchronization channel (P-SCH) anda secondary synchronization channel (S-SCH) from the base station, andacquires information such as cell ID, etc. Afterwards, the userequipment may acquire broadcast information within the cell by receivinga physical broadcast channel (PBCH) from the base station. Meanwhile,the user equipment may identify a downlink channel status by receiving adownlink reference signal (DL RS) at the initial cell search step.

The user equipment which has finished the initial cell search mayacquire more detailed system information by receiving a physicaldownlink shared channel (PDSCH) in accordance with a physical downlinkcontrol channel (PDCCH) and information carried in the PDCCH at stepS302.

Afterwards, the user equipment may perform a random access procedure(RACH) such as steps S303 to S306 to complete access to the basestation. To this end, the user equipment may transmit a preamble througha physical random access channel (PRACH) (S303), and may receive aresponse message to the preamble through the PDCCH and the PDSCHcorresponding to the PDCCH (S304). In case of a contention based RACH,the user equipment may perform a contention resolution procedure such astransmission (S305) of additional physical random access channel andreception (S306) of the physical downlink control channel and thephysical downlink shared channel corresponding to the physical downlinkcontrol channel.

The user equipment which has performed the aforementioned steps mayreceive the physical downlink control channel (PDCCH)/physical downlinkshared channel (PDSCH) (S307) and transmit a physical uplink sharedchannel (PUSCH) and a physical uplink control channel (PUCCH) (S308), asa general procedure of transmitting uplink/downlink signals. Controlinformation transmitted from the user equipment to the base station willbe referred to as uplink control information (UCI). The UCI includesHARQ ACK/NACK (Hybrid Automatic Repeat and reQuestAcknowledgement/Negative-ACK), SR (Scheduling Request), CSI (ChannelState Information), etc. In this specification, the HARQ ACK/NACK willbe referred to as HARQ-ACK or ACK/NACK (A/N). The HARQ-ACK includes atleast one of positive ACK (simply, referred to as ACK), negative ACK(NACK), DTX and NACK/DTX. The CSI includes CQI (Channel QualityIndicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc.Although the UCI is generally transmitted through the PUCCH, it may betransmitted through the PUSCH if control information and traffic datashould be transmitted at the same time. Also, the user equipment maynon-periodically transmit the UCI through the PUSCH in accordance withrequest/command of the network.

FIG. 4 is a diagram illustrating a structure of a radio frame used in anLTE system.

Referring to FIG. 4, in a cellular OFDM radio packet communicationsystem, uplink/downlink data packet transmission is performed in a unitof subframe, wherein one subframe is defined by a given time intervalthat includes a plurality of OFDM symbols. The 3GPP LTE standardsupports a type 1 radio frame structure applicable to frequency divisionduplex (FDD) and a type 2 radio frame structure applicable to timedivision duplex (TDD).

FIG. 4(a) is a diagram illustrating a structure of a type 1 radio frame.The downlink radio frame includes 10 subframes, each of which includestwo slots in a time domain. A time required to transmit one subframewill be referred to as a transmission time interval (TTI). For example,one subframe may have a length of 1 ms, and one slot may have a lengthof 0.5 ms. One slot includes a plurality of OFDM symbols in a timedomain and a plurality of resource blocks (RB) in a frequency domain.Since the 3GPP LTE system uses OFDM in a downlink, OFDM symbolsrepresent one symbol interval. The OFDM symbol may be referred to asSC-FDMA symbol or symbol interval. The resource block (RB) as a resourceallocation unit may include a plurality of continuous subcarriers in oneslot.

The number of OFDM symbols included in one slot may be varied dependingon configuration of a cyclic prefix (CP). Examples of the CP include anextended CP and a normal CP. For example, if the OFDM symbols areconfigured by the normal CP, the number of OFDM symbols included in oneslot may be 7. If the OFDM symbols are configured by the extended CP,since the length of one OFDM symbol is increased, the number of OFDMsymbols included in one slot is smaller than that of OFDM symbols incase of the normal CP. For example, in case of the extended CP, thenumber of OFDM symbols included in one slot may be 6. If a channel stateis unstable like the case where the user equipment moves at high speed,the extended CP may be used to reduce inter-symbol interference.

If the normal CP is used, since one slot includes seven OFDM symbols,one subframe includes 14 OFDM symbols. At this time, first maximum threeOFDM symbols of each subframe may be allocated to a physical downlinkcontrol channel (PDCCH), and the other OFDM symbols may be allocated toa physical downlink shared channel (PDSCH).

FIG. 4(b) is a diagram illustrating a structure of a type 2 radio frame.The type 2 radio frame includes two half frames, each of which includesfour general subframes, which include two slots, and a special subframewhich includes a downlink pilot time slot (DwPTS), a guard period (GP),and an uplink pilot time slot (UpPTS).

In the special subframe, the DwPTS is used for initial cell search,synchronization or channel estimation at the user equipment. The UpPTSis used for channel estimation at the base station and uplinktransmission synchronization of the user equipment. In other words, theDwPTS is used for downlink transmission, whereas the UpPTS is used foruplink transmission. Especially, the UpPTS is used for PRACH preamble orSRS transmission. Also, the guard period is to remove interferenceoccurring in the uplink due to multipath delay of downlink signalsbetween the uplink and the downlink.

Configuration of the special subframe is defined in the current 3GPPstandard document as illustrated in Table 1 below. Table 1 illustratesthe DwPTS and the UpPTS in case of T_(s)=015000×2048), and the otherregion is configured for the guard period.

TABLE 1 Normal cyclic prefix in downlink Extended cyclic prefix indownlink UpPTS UpPTS Normal Extended Normal Extended Special cycliccyclic cyclic cyclic subframe prefix in prefix in prefix in prefix inconfiguration DwPTS uplink uplink DwPTS uplink uplink 0  6592 · T_(s)2192 · T_(s) 2560 · T_(s)  7680 · T_(s) 2192 · T_(s) 2560 · T_(s) 119760 · T_(s) 20480 · T_(s) 2 21952 · T_(s) 23040 · T_(s) 3 24144 ·T_(s) 25600 · T_(s) 4 26336 · T_(s)  7680 · T_(s) 4384 · T_(s) 5120 ·T_(s) 5  6592 · T_(s) 4384 · T_(s) 5120 · T_(s) 20480 · T_(s) 6 19760 ·T_(s) 23040 · T_(s) 7 21952 · T_(s) 12800 · T_(s) 8 24144 · T_(s) — — —9 13168 · T_(s) — — —

In the meantime, the structure of the type 2 radio frame, that is,uplink/downlink configuration (UL/DL configuration) in the TDD system isas illustrated in Table 2 below.

TABLE 2 Downlink- to-Uplink Uplink- Switch- downlink point Subframenumber configuration periodicity 0 1 2 3 4 5 6 7 8 9 0  5 ms D S U U U DS U U U 1  5 ms D S U U D D S U U D 2  5 ms D S U D D D S U D D 3 10 msD S U U U D D D D D 4 10 ms D S U U D D D D D D 5 10 ms D S U D D D D DD D 6  5 ms D S U U U D S U U D

In the above Table 2, D means the downlink subframe, U means the uplinksubframe, and S means the special subframe. Also, Table 2 alsoillustrates a downlink-uplink switching period in the uplink/downlinksubframe configuration of each system.

The structure of the aforementioned radio frame is only exemplary, andvarious modifications may be made in the number of subframes included inthe radio frame, the number of slots included in the subframe, or thenumber of symbols included in the slot.

FIG. 5 is a diagram illustrating a resource grid of a downlink slot.

Referring to FIG. 5, the downlink slot includes a plurality of N_(symb)^(DL) OFDM symbols in a time domain and a plurality of N_(RB) ^(DL)resource blocks in a frequency domain. Since each resource blockincludes N_(sc) ^(RB) subcarriers, the downlink slot includes N_(RB)^(DL)=N_(sc) ^(RB) subcarriers in the frequency domain. Although FIG. 5illustrates that the downlink slot includes seven OFDM symbols and theresource block includes twelve subcarriers, it is to be understood thatthe downlink slot and the resource block are not limited to the exampleof FIG. 5. For example, the number of OFDM symbols included in thedownlink slot may be varied depending on the length of the CP.

Each element on the resource grid will be referred to as a resourceelement (RE). One resource element is indicated by one OFDM symbol indexand one subcarrier index. One RB includes N_(symb) ^(DL)×N_(sc) ^(RB)number of resource elements. The number N_(RB) ^(DL) of resource blocksincluded in the downlink slot depends on a downlink transmissionbandwidth configured in the cell.

FIG. 6 shows a configuration of a downlink subframe.

Referring to FIG. 6, maximum 3 (4) OFDM symbols situated in a head partof a first slot of a subframe correspond to a control region to whichcontrol channels are assigned. The rest of OFDM symbols correspond to adata region to which PDSCH (physical downlink shared channel) isassigned. Examples of DL (downlink) control channels used by 3GPP LTEmay include PCFICH (Physical Control Format Indicator Channel), PDCCH(Physical Downlink Control Channel), PHICH (Physical hybrid automaticrepeat request indicator Channel) and the like. The PCFICH istransmitted in a first OFDM symbol of a subframe and carries informationon the number of OFDM symbols used for a transmission of a controlchannel within the subframe. The PHICH carries HARQ ACK/NACK(acknowledgement/negative-acknowledgement) signal in response to UL(uplink) transmission.

Control information carried on PDCCH may be called a downlink controlinformation (hereinafter abbreviated DCI). The DCI may include aresource allocation information for a user equipment or a user equipmentgroup and other control informations. For instance, the DCI includesUL/DL scheduling information, UL transmission (Tx) power controlcommand, power control command, and the like.

PDCCH carries a transmission format and resource allocation of DL-SCH(downlink shared channel), a resource allocation information on UL-SCH(uplink shared channel), a paging information on PCH (paging channel), asystem information on DL-SCH, a resource allocation information such asa random access response transmitted on PDSCH, a transmission powercontrol command for an individual user equipment in a random userequipment (UE) group, an activation of VoIP (voice over IP) and thelike. A plurality of PDCCHs can be transmitted within a control region.A user equipment is able to monitor a plurality of the PDCCHs. PDCCH istransmitted on a single CCE (control channel element) or an aggregationof a plurality of consecutive CCEs. The CCE is a logical assignment unitused to provide PDCCH of a prescribed coding rate in accordance with astate of a radio channel. The CCE corresponds to a plurality of REGs(resource element group). A format of PDCCH and the bit number ofavailable PDCCH are determined in accordance with a correlation betweenthe number of CCEs and a coding rate provided by CCE. A base stationdetermined a PDCCH format depending on a DCI which is to be transmittedto a user equipment and attaches a CRC (cyclic redundancy check) to acontrol information. The CRC is masked with a unique identifier (RNTI(radio network temporary identifier) in accordance with an owner orusage of PDCCH. For instance, if PDCCH is provided for a specific userequipment, an identifier (e.g., C-RNTI (cell-RNTI)) of the correspondinguser equipment is masked on a CRC. If PDCCH is provided for a pagingmessage, a paging identifier (e.g., P-RNTI (paging-RNTI) can be maskedon a CRC. If PDCCH is provided for a system information (moreparticularly, system information block (SIC)), SI-RNTI (systeminformation-RNTI) can be masked on a CRC. If PDCCH is provided for arandom access response, RA-RNTI (random access-RNTI) can be masked on aCRC.

FIG. 7 shows a resource unit used in configuring a downlink controlchannel in LTE system. In particular, FIG. 7 (a) shows a case that thenumber of transmitting antenna(s) of a base station is 1 or 2. And, FIG.7 (b) shows a case that the number of transmitting antennas of a basestation is 4. The cases differ from each other in RS (reference signal)pattern but have the same method of configuring a resource unit relatedto a control channel.

Referring to FIG. 7, a basic resource unit of a control channel is REG.The REG includes 4 neighboring resource elements (REs) except RS. TheREG is indicated by a bold line in the drawing. PCFICH and PHICH include4 REGs and 3 REGs, respectively. PDCCH is configured by CCE (controlchannel elements) unit and one CCE includes 9 REGs.

A user equipment is set to check M^((L)) (≧L) CCEs, which are contiguousto each other or arranged by specific rules, in order to check whetherPDCCH configured with L CCEs is transmitted to the corresponding userequipment. The L value, which should be considered by the user equipmentfor PDCCH reception, may become a plural number. CCE sets, which shouldbe checked by the user equipment for the PDCCH reception, are called asearch space. For instance, LTE system defines a search space as Table3.

TABLE 3 Search space S_(k) ^((L)) Number of PDCCH Type Aggregation levelL Size [in CCEs] candidates M^((L)) UE- 1 6 6 Specific 2 12 6 4 8 2 8 162 Common 4 16 4 8 16 2

In Table 3, CCE aggregation level L indicates the number of CCEsconfiguring PDCCH, S_(k) ^((L)) indicates a search space of the CCEaggregation level L, and M^((L)) indicates the number of PDCCHcandidates supposed to be monitored in the search space of theaggregation level L.

The search space may be categorized into a UE-specific search spaceaccessible by a specific user equipment only and a common search spaceaccessible by all user equipments in a cell. A user equipment monitors acommon search space having a CCE aggregation level set to 4 or 8 and aUE-specific search space having a CCE aggregation level set to 1, 2, 4or 8. And, the common search space and the UE-specific search space mayoverlap each other.

Moreover, a position of a 1^(st) CCE (i.e., CCE having a smallest index)in PDCCH search space given to a random user equipment for each CCEaggregation level value may vary in each subframe according to a userequipment. This may be called a PDCCH search space hashing.

The CCE may be dispersed on a system band. In particular, a plurality ofCCEs logically contiguous to each other can be inputted to aninterleaver. And, the interleaver performs a function of mixing aplurality of the inputted CCEs. Hence, frequency/time resourcesconfiguring a single CCE are physically scattered and distributed on awhole frequency/time domain within a control region of a subframe.Eventually, although a control channel is configured by CCE units, asinterleaving is performed by REG units, it is able to maximize frequencydiversity and interference randomization gain.

FIG. 8 shows one example of a carrier aggregation (CA) communicationsystem.

Referring to FIG. 8, a plurality of UL/DL CCs (uplink/downlink componentcarriers) are aggregated so as to support a wider UL/DL bandwidth. Theterminology ‘component carrier (CC)’ can be substituted with anotherequivalent terminology (e.g., carrier, cell, etc.). The respective CCsmay be adjacent or non-adjacent to each other in a frequency domain. Abandwidth of each of the component carriers may be determinedindependently. It is possible to configure asymmetric carrieraggregation in which the number of UL CCs is different from that of DLCCs. Meanwhile, a control information may be set to be transceivedthrough a specific CC only. Such a specific CC may be named a primary CC(or an anchor CC), while other CCs may be named secondary CCs.

In case of applying a cross-carrier scheduling (or a cross-CCscheduling), a PDCCH for a DL assignment may be transmitted on DL CC #0and a corresponding PDSCH may be transmitted on DL CC #2. For thecross-CC scheduling, it may be able to consider an introduction of acarrier indicator field (CIF). A presence or non-presence of a CIF inPDCCH can be set by an upper layer signaling (e.g., RRC signaling) in asemi-static manner of a UE-specific (or UE group-specific) manner Abaseline of PDCCH transmission is summarized as follows.

-   -   CIF disabled: PDCCH on DL CC allocates PDSCH resource on the        same DL CC or PUSCH resource on a linked UL CC.    -   No CIF    -   Same as LTE PDCCH structure (same coding, same CCE-based        resource mapping) and DCI format    -   CIF enabled: PDCCH on DL CC can allocate PDSCH or PUSCH resource        on a specific DL/UL CC among a plurality of aggregated DL/UL CCs        using CIF.    -   Extended LTE DCI format having CIF        -   CIF (enabled) corresponds to a fixed x-bit field (e.g., x=3)        -   CIF (enabled) location is fixed irrespective of DCI format            size    -   Reuse LTE PDCCH structure (same coding, same CC-based resource        mapping)

If CIF is present, a base station is able to assign a PDCCH monitoringDL CC set to lower BD complexity of a user equipment side. The PDCCHmonitoring DL CC set includes at least one DL CC as apportion of full DLCCs and a user equipment performs detection/decoding of PDCCH on thecorresponding DL CC only. In particular, in case that a base stationschedules PDSCH/PUSCH for a user equipment, the PDCCH is transmitted ona PDCCH monitoring DL CC set only. The PDCCH monitoring DL CC set can beconfigured in a UE-specific manner, a UE-group-specific manner, or acell-specific manner. The terminology ‘PDCCH monitoring DL CC set’ canbe substituted with such an equivalent terminology as a monitoringcarrier, a monitoring cell or the like. Moreover, a CC aggregated for auser equipment can be substituted with such an equivalent terminology asa serving CC, a serving carrier, a serving cell or the like.

FIG. 9 shows one example of a scheduling in case of aggregating aplurality of carriers. Assume that 3 DL CCs are aggregated. Assume thatDL CC A is configured as a PDCCH monitoring DL CC. DL CC A˜C may becalled a serving CC, a serving carrier, a serving cell, or the like. Ifa CIF is disabled, each DL CC can transmit only a PDCCH for schedulingits PDSCH without CIF in accordance with LTE PDCCH configuration. On theother hand, if a CIF is enabled by a UE-specific (or, UE-group-specific,cell-specific) upper layer signaling, DL CC A (i.e., a monitoring DL CC)can transmit not only a PDCCH for scheduling a PDSCH of DL CC A but alsoa PDCCH for scheduling a PDSCH of another CC using the CIF. In thiscase, a PDCCH is not transmitted on DL CC B/C failing to be set as aPDCCH monitoring DL CC. Hence, the DL CC A (i.e., the monitoring DL CC)should include a PDCCH search space related to the DL CC A, a PDCCHsearch space related to the DL CC B and a PDCCH search space related tothe DL CC C all. In the present specification, assume that a PDCCHsearch space is defined for each carrier.

As mentioned in the foregoing description, LTE-A currently considersusing a CIF within PDCCH for cross-CC scheduling. A presence ornon-presence of a use of a CIF (i.e., a support of a cross-CC schedulingmode or a non-cross-CC scheduling mode) and an inter-mode switching maybe configured semi-statically/UE-specifically through an RRC signaling.After a user equipment has gone through the corresponding RRC signaling,the user equipment is able to recognize whether a CIF is used within aPDCCH that will be scheduled for the corresponding user equipment.

FIG. 10 shows one example of EPDCCH and PDSCH scheduled by EPDCCH.

Referring to FIG. 10, EPDCCH is able to define and use a portion of aPDSCH region for transmitting data in general. And, a user equipmentshould perform a blind decoding process for detecting a presence ornon-presence of its EPDCCH. Although the EPDCCH performs the samescheduling operation (i.e., PDSCH/PUSCH control) of an existing legacyPDCCH, if the number of user equipments currently accessing such a nodeas RRH increases, a great number of EPDCCHs are assigned within a PRSCHregion to increase a count of blind decodings the user equipment shouldperform. Hence, it is disadvantageous in that complexity may increase.

In the following description, CoMP (cooperative multipointtransmission/reception) is described.

Since LTE-A, systems intend to employ a scheme of raising performance ofsystem by enabling cooperation among several cells. Such a scheme iscalled cooperative multipoint transmission/reception (CoMP). The CoMPmeans a scheme that at least two base stations, access points or cellscommunicate with a user equipment cooperatively in order to performcommunication between a specific user equipment and a base station, anaccess point or a cell more smoothly. In the present invention, a basestation, an access point or a cell may be used for the same meaning.

Generally, in a multi-cell environment having a frequency reuse factorset to 1, the performance and average sector throughput of a userequipment located at the cell edge may be lowered due to inter-cellinterference (ICI). In order to reduce the ICI, a conventional LTEsystem has employed a method of providing an appropriate throughputperformance to a user equipment located at a cell edge in an environmentrestricted by interference using a simple passive scheme such as FFR(fractional frequency reuse) via UE-specific power control. Yet,reducing the ICI or reusing the ICI as a signal desired by a userequipment may be more preferable than lowering a frequency resource useper cell. To achieve this object, CoMP transmission schemes may beapplicable.

FIG. 11 shows one example of performing CoMP. referring to FIG. 11, awireless communication system includes a plurality of base stations BS1,BS2 and BS3 configured to perform CoMP and a user equipment. A pluralityof the base stations BS1, BS2 and BS3 can transmit data to the userequipment efficiently by cooperating with each other. CoMP can beclassified into two types depending on whether data is transmitted fromeach base station configured to perform CoMP as follows.

-   -   Joint Processing (CoMP Joint Processing: CoMP-JP)        -   Cooperative Scheduling/Beamforming (CoMP-CS/CB, CoMP            Cooperative Scheduling: CoMP-CS)

In case of CoMP-JP, data toward a single user equipment aresimultaneously transmitted to the user equipment from the respectivebase stations performing CoMP and the user equipment improves receptionperformance by combining signals from the respective base stationstogether. In particular, CoMP-JP scheme can use data at each point(e.g., base station) of CoMP cooperation unit. And, the CoMP cooperationunit may mean a set of base stations used for the cooperativetransmission scheme. The JP scheme may be classified into a jointtransmission scheme and a dynamic cell selection scheme.

The joint transmission scheme means a scheme of transmitting PDSCH froma plurality of points (portion or all of CoMP cooperation unit) at atime. In particular, data transmitted to a single user equipment may besimultaneously from a plurality of transmission points. According to thejoint transmission scheme, a quality of a coherently or non-coherentlyreceived signal can be improved and interference on another userequipment can be actively eliminated.

The dynamic cell selection scheme means the scheme of transmitting PDSCHfrom one point (of CoMP cooperation unit) at a time. In particular, datatransmitted to a single user equipment at a specific timing point istransmitted from one point, the rest of points in the cooperation unitat that timing point do not perform data transmission to thecorresponding user equipment, and a point transmitting data to thecorresponding user equipment may be dynamically selected.

On the other hand, in case of CoMP-CS, data to one user equipment istransmitted through one base station at a random timing point andscheduling or beamforming is performed to minimize interference causedby another base station. In particular, according to the CS/CB scheme,CoMP cooperation units can cooperatively perform beamforming of datatransmission to a single user equipment. In this case, although data istransmitted from a serving cell only, user scheduling/beamforming may bedetermined by the coordination of cells of the corresponding CoMPcooperation unit.

Meanwhile, in case of uplink, coordinated multi-point reception meansthat a signal transmitted by coordination of a plurality of pointsgeographically spaced apart from each other is received. CoMP schemesapplicable to a case of uplink may be classified into joint reception(JR) and coordinated scheduling/coordinated beamforming (CS/CB).

The JR scheme means that a signal transmitted on PUSCH is received by aplurality of reception points. And, the CS/CB scheme means that userscheduling/beamforming is determined by coordination of cells of CoMPcooperation unit despite that PUSCH is received by one point only.

Interference among multiple cells is described as follows.

Like a case that two base stations (e.g., base station #1 and basestation #2) are disposed adjacently, if coverages of the two basestations overlap with each other in part, a strong DL signal from onebase station may cause interference to a user equipment served by theother base station. Thus, in case that inter-cell interference occurs,it is able to reduce the inter-cell interference through an inter-cellcooperation signal scheme between two base stations. In variousembodiments of the present invention described in the following, assumea case that signal transmission and reception between two base stationscausing interference to each other is performed smoothly. For instance,as wired/wireless link (e.g., backhaul link, Un interface, etc.) havinga good transmission condition (e.g., transmission bandwidth, time delay,etc.) exists between two base stations, assume a case that reliabilityon transmission and reception of a cooperative signal between basestations is high. Moreover, it is able to assume a case that timesynchronization between two base stations coincides (e.g., edges of DLsubframes of two base stations exchanging interference with each otherare aligned) or a case that offset of subframe boundaries between twobase stations is recognized clearly and mutually.

Referring now to FIG. 11, the base station #1 (BS #1) may include amacro base station servicing a wide area with high transmission power,while the base station #2 (BS #2) may include a micro base station(e.g., pico base station) servicing a small area with low transmissionpower. When a user equipment (UE) served by the base station #2 by beinglocated in a cell edge area of the base station #2 receives stronginterference from the base station #1, as shown in FIG. 11, it may bedifficult to perform communication effectively without appropriateinter-cell cooperation.

Particularly, in case that the base station #1 (i.e., macro basestation) intends to disperse load for providing a service by connectingmany user equipments to the base station #2 (i.e., micro base station)having low power, it is highly probable that the above-mentionedsituation of inter-cell interference occurs. For instance, in case thata user equipment intends to select a serving base station, it is able tocalculate and compare a reception power of a DL signal from each basestation in a manner of adding a prescribed coordination value (e.g.,bias value) to a reception power from a micro base station but notadding a coordination value to a reception power from a macro basestation. As a result, the user equipment can select a base stationproviding a highest DL reception power as a serving base station.Accordingly, more user equipments can be connected to the micro basestation. Regarding DL signal strength actually received by a userequipment, despite that a signal from a macro base station is muchstronger, a micro base station can be selected as a serving basestation. And, the user equipment connected to the micro base station canexperience strong interference from the macro base station. In thiscase, user equipments located on the edge of the micro base station mayhave difficulty in performing correct operations due to the stronginterference from the macro base station if separate inter-cellcooperation is not provided.

When inter-cell interference exists, in order to perform effectiveoperation, appropriate cooperation should be performed between two basestations exchanging the inter-cell interference with each other. And, asignal for enabling such cooperative operation can be transceived in alink between the two base stations. In doing so, if inter-cellinterference occurs between a macro base station and a micro basestation, the macro base station controls inter-cell cooperationoperation and the micro base station can perform an appropriateoperation according to a cooperation signal indicated by the macro basestation.

The above inter-cell interference occurrence situation is justexemplary. And, it is apparent that embodiments described in the presentinvention are exactly applicable to cases (e.g., case of occurrence ofinter-cell interference between HeNB of CSG and macro base station ofOSG, case of interference caused to macro base station by micro basestation, case of presence of inter-cell interference between micro basestation and macro base station, etc.) of occurrence of inter-cellinterference in situation different from the above.

FIG. 12 shows a case that a specific cell changes to use a portion of anexisting UL resource (i.e., UL SF) for the purpose of DL communicationif a quantity of DL load of a system increases in TDD systemenvironment.

In FIG. 12, UL-DL configuration through SIB is assumed as UL-DL #1(i.e., DSUUDDSUUD). And, FIG. 12 shows a case that existing UL SF #(n+3)and UL SF #(n+8) are used in a manner of changing usages of existing ULSF #(n+3) and UL SF #(n+8) for DL communication through a pre-definedsignal (e.g., physical/upper layer signal, system information signal,etc.).

1. UL-DL Configuration Application According to the Present Invention

The present invention proposes a method for a user equipment (e.g.,eIMTA UE) having received a multitude of radio resource usage (re)changemessages (UL-DL Reconfiguration DCI or radio resource usagereconfiguration control information) in a pre-defined specific timeinterval (e.g., Monitoring Window for UL-DL Reconfiguration DCI, orReception Window for UL-DL Reconfiguration DCI)) to efficientlydetermine/select UL-DL configuration actually applied to a linked radioresource usage (re)change message application duration (Validation Widowof Received UL-DL Reconfiguration DCI, or Application Widow of ReceivedUL-DL Reconfiguration DCI). In the following description of the presentinvention, information for changing/reconfiguring the preset usage ofradio resource is named a usage reconfiguration message (ReconfigurationDCI), which is for clarity and convenience of the description of thepresent invention only. In some cases, although the information is namedradio resource usage reconfiguration control information, it may beinterpreted as the same information in the application of the presentinvention.

For clarity of the following description, the present invention isdescribed based on 3GPP LTE system. Yet, the scope of the presentinvention applicable systems can be extended to other systems as well asto the 3GPP LTE system.

Embodiments of the present invention are extensively applicable to acase that resource on specific cell or specific component carrier (CC)is dynamically changed according to load state of system in CA (carrieraggregation) applied environment.

And, embodiments of the present invention are extensively applicable toa case that usage of radio resource is dynamically changed in TDDsystem, FDD system, or TDD/FDD merged system.

For clarity of the following description of the present invention,assume a situation that each cell dynamically changes a usage of anexisting radio resource according to system load state of its own.

1-1. Configuration of Radio Resource Usage (Re)Configuration Message

Prior to the detailed description of the present invention, a radioresource usage (re)configuration message (hereinafter named UL-DLreconfiguration DCI) can be configured and transmitted/applied based onthe rules described in the following. In this case, ‘T’ may beinterpreted as update periodicity of UL-DL reconfiguration DCI (or,update periodicity of UL-DL configuration.

First of all, the configuration of a radio resource usage(re)configuration message (UL-DL reconfiguration DCI) for the presentinvention is described. New RNTI for an explicit radio resource usage(re)configuration message (UL-DL reconfiguration DCI) can be defined.And, the radio resource usage (re)configuration message (UL-DLreconfiguration DCI) is transmitted with at least 3 bits to explicitlyindicate one of 7 UL-DL configurations. In this case, the radio resourceusage (re)configuration message (UL-DL reconfiguration DCI) can betransmitted on PDCCH common search space of Pcell.

If a user equipment uses a multitude of eIMTA-enabled cells, the userequipment can receive indication of radio resource usage(re)configuration message (UL-DL reconfiguration DCI) for a multitude ofthe eIMTA-enabled cells using DCI transmitted on PDCCH CSS of Pcell. Inthis case, if DCI is transmitted on PDCCH CSS of Pcell, a multitude ofindicators (3 bits per indicator) for a multitude of the eIMTA-enabledcells may be included in one explicit radio resource usage(re)configuration message (UL-DL reconfiguration DCI) for a multitude ofthe eIMTA-enabled cells.

Furthermore, a group common DCI for a user equipment can be transmittedon a common search space of Pcell only.

1-2. Transmission/Reception and Application of Radio Resource Usage(Re)Configuration Message (UL-DL Reconfiguration DCI)

A user equipment is set to monitor radio resource usage(re)configuration message on subframes that meet ‘(10·n_(f)+n−k) modT=0’. In this case, n is a subframe number in a radio frame and n_(j) isa radio frame number. T and k are defined in Table 4.

UL-DL configuration indicated by a radio resource usage(re)configuration message received in a subframe of a radio frame{m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} is valid at {m·T/10, m·T/10+1,. . . , (m+1)·T/10−1} (hereinafter named “Current”) or {(m+1)·T/10,(m+1)·T/10+1, . . . , (m+2)·T/10−1} (hereinafter named “Next”) accordingto Table 4. Moreover, it is not necessary for the user equipment to wakeup to monitor a radio resource usage (re)configuration message in DRXOFF state. In this case, ‘m; is an arbitrary integer (e.g., positiveinteger including 0, positive integer, etc.).

Operations of a user equipment related to a radio resource usage(re)configuration message are defined as follows.

Operation 1: If a user equipment is set to monitor a radio resourceusage (re)configuration message on a multitude of subframes for a radioframe {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} if at least one radioresource usage (re)configuration message is successfully decoded on theradio frame {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} the user equipmentcan skip the decoding of the radio resource usage (re)configurationmessage on the radio frame {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1}.

Operation 2: If a user equipment is set to monitor a radio resourceusage (re)configuration message on a multitude of subframes for a radioframe {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1}, the user equipment canregard it as the same UL-DL configuration indicated on the radioresource usage (re)configuration message on the radio frame {m·T/10,m·T/10+1, . . . , (m+1)·T/10−1}.

TABLE 4 Periodicity T (ms) Offset k (ms) (0 ≦ k < T) Valid duration 10 AX-bit bitmap to indicate a set of “Current” for the SIB-1 DL/S subframe.Starting reconfiguration from the MSB to LSB, the bitmap DCI incorresponds to subframe subframe #0 #{[Xa, Xb, Xc, . . . ]}. The “Next”for the bit “1” indicates that UE shall reconfiguration DCI monitor thereconfiguration DCI in in the SIB1 DL/S the corresponding subframe,subframes other and the bit “0” indicates otherwise. than subframe #0 20A Y-bit bitmap to indicate a set [“Current” for the of SIB-1 DL/Ssubframe. Starting reconfiguration from the MSB to LSB, the bitmap DCIin corresponds to subframe subframe #0 in the #{[Ya, Yb, Yc, . . . ]}.The first radio bit “1” indicates that UE frame in the shall monitor thewindow, if reconfiguration DCI in the supported by the correspondingsubframe, Y-bit bitmap] and the bit “0” indicates otherwise. “Next” forthe reconfiguration DCI in the SIB1 DL/S subframes other than subframein the first radio frame in the window 40 A Z-bit bitmap to indicate a[“Current” for the set of SIB-1 DL/S reconfiguration subframe. Startingfrom the MSB DCI in to LSB, the bitmap subframe #0 in corresponds tosubframe the first radio #{[Za, Zb, Zc, . . . ]}. The bit frame in the“1” indicates that UE shall monitor window, if the reconfiguration DCIin the supported by the corresponding subframe, Z-bit bitmap] and thebit “0” indicates otherwise. “Next” for the reconfiguration DCI in theSIB1 DL/S subframes other than subframe #0 in the first radio frame inthe window 80 A Q-bit bitmap to indicate a [“Current” for the set ofSIB-1 DL/S reconfiguration subframe. Starting from the DCI in MSB toLSB, the bitmap subframe #0 corresponds to subframe in the first radio#{[Qa, Qb, Qc, . . . ]}. The frame in the bit “1” indicates that UEwindow, if shall monitor the supported by reconfiguration DCI in the theQ-bit bitmap] corresponding subframe, “Next” for the and the bit “0”indicates otherwise. reconfiguration DCI in the SIB1 DL/S subframesother than subframe #0 in the first radio frame in the window

In Table 4, signal periodicity for usage change of a radio resource isdetermined to include 10 ms, 20 ms and 40 ms at least. With respect tothe periodicity of 10 ms, the number of X is minimum 4 and subframe#{[Xa, Xb, Xc, . . . ]} includes subframe #{0, 1, 5, 6} at least. Withrespect to the periodicity of 20 ms, the number of Y is minimum 4 andsubframe #{[Ya, Yb, Yc, . . . ]} includes subframe #{0, 1, 5, 6} atleast in a second radio frame of the aforementioned applicationinterval. With respect the periodicity of 40 ms, the number of Z isminimum 4 and #{[Za, Zb, Zc, . . . ]} includes subframe #{0, 1, 5, 6} atleast in a fourth radio frame of the aforementioned applicationinterval. With respect the periodicity of 80 ms, the number of Q isminimum 4 and subframe #{[Qa, Qb, Qc, . . . ]} includes subframe #{0, 1,5, 6} at least in an eighth radio frame of the aforementionedapplication interval. In this case, a user equipment is set not tomonitor radio resource usage (re)configuration message in non-SIB-1downlink/special subframes.

In particular, in ‘1-1. Configuration of radio resource usage(re)configuration message’ and ‘1-2. Transmission/reception andapplication of radio resource usage (re)configuration message (UL-DLreconfiguration DCI)’, a user equipment (hereinafter called eIMTA UE)set to monitor a multitude of radio resource usage (re)configurationmessages (UL-DL reconfiguration DCI) on a multitude of subframes(indicated by bitmap) on radio frame(s) {m·T/10, m·T/10+1, . . . ,(m+1)·T/10−1} can be set to: i) decode a previously defined (orsignaled) number of radio resource usage (re)configuration messagesamong a multitude of the radio resource usage (re)configuration messagesand then apply valid UL-DL configuration determined per individual cellto a linked valid duration; or ii) decode a multitude of the radioresource usage (re)configuration messages all and then apply valid UL-DLconfiguration determined per individual cell to a linked valid duration(e.g., {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} (i.e., “Current”), or{(m+1)·T/10, (m+1)·T/10+1, . . . , (m+2)·T/10−1} (i.e., “Next”)),according to first to seventh methods proposed in the following.Moreover, signaling for radio resource usage (re)configuration messagescan be signaled through an upper or physical layer.

2. Embodiment of the Present Invention 2-1. First Method

According to a first method of the present invention, a user equipment(hereinafter called eIMTA UE) set to monitor a multitude of radioresource usage (re)configuration messages (UL-DL reconfiguration DCI) ona multitude of subframes (indicated by bitmap) on radio frame(s){m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} can be set to: i) decode only apreviously defined (or signaled) number of radio resource usage(re)configuration messages among a multitude of the radio resource usage(re)configuration messages and then apply valid UL-DL configuration mostsuccessfully detected per individual cell to a linked valid duration; orii) decode a multitude of the radio resource usage (re)configurationmessages all and then apply valid UL-DL configuration most successfullydetected per individual cell to a linked valid duration.

For instance, the valid UL-DL configuration successfully detected perindividual cell may mean at least one of: i) UL-DL configurationdetected as radio resource usage (re)configuration message (UL-DLreconfiguration DCI) related CRC check is true; ii) UL-DL configurationof not changing UL frame on reference DL HARQ timeline related UL-DLconfiguration for downlink usage; and iii) UL-DL configuration of notchanging UL frame on reference DL HARQ timeline related UL-DLconfiguration for uplink usage.

2-2. Second Method

According to a second method of the present invention, a user equipment(hereinafter called eIMTA UE) set to monitor a multitude of radioresource usage (re)configuration messages (UL-DL reconfiguration DCI) ona multitude of subframes (indicated by bitmap) on radio frame(s){m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} can be set to: i) decode only apreviously defined (or signaled) number of radio resource usage(re)configuration messages among a multitude of the radio resource usage(re)configuration messages and then apply valid UL-DL configurationdetected first successfully detected per individual cell to a linkedvalid duration; or ii) decode a multitude of the radio resource usage(re)configuration messages all and then apply valid UL-DL configurationdetected first successfully per individual cell to a linked validduration. On the contrary, the user equipment may be set to: i) decodeonly a previously defined (or signaled) number of radio resource usage(re)configuration messages among a multitude of the radio resource usage(re)configuration messages and then apply valid UL-DL configurationdetected last successfully detected per individual cell to a linkedvalid duration; or ii) decode a multitude of the radio resource usage(re)configuration messages all and then apply valid UL-DL configurationdetected last successfully per individual cell to a linked validduration.

For instance, the valid UL-DL configuration successfully detected perindividual cell may mean at least one of: i) UL-DL configurationdetected as radio resource usage (re)configuration message (UL-DLreconfiguration DCI) related CRC check is true; ii) UL-DL configurationof not changing UL frame on reference DL HARQ timeline related UL-DLconfiguration for downlink usage; and iii) UL-DL configuration of notchanging UL frame on reference DL HARQ timeline related UL-DLconfiguration for uplink usage.

2-3. Third Method

According to a third method of the present invention, a user equipment(hereinafter called eIMTA UE) set to monitor a multitude of radioresource usage (re)configuration messages (UL-DL reconfiguration DCI) ona multitude of subframes (indicated by bitmap) on radio frame(s){m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} can be set to: i) decode only apreviously defined (or signaled) number of radio resource usage(re)configuration messages (UL-DL reconfiguration DCI) among a multitudeof the radio resource usage (re)configuration messages (UL-DLreconfiguration DCI) and then apply a predefined fallback mode relatedUL-DL configuration to a linked valid duration if all ‘successfullydetected UL-DL configurations’ (or ‘successfully detected valid UL-DLconfigurations’) per each cell are not equal to each other; or ii)decode a multitude of the radio resource usage (re)configurationmessages (UL-DL reconfiguration DCI) all and then apply a predefinedfallback mode related UL-DL configuration to a linked valid duration ifall ‘successfully detected UL-DL configurations’ (or ‘successfullydetected valid UL-DL configurations’) per each cell are not equal toeach other. Moreover, if at least one of ‘successfully detected UL-DLconfigurations’ (or ‘successfully detected valid UL-DL configurations’)per each cell is different, the present method can be interpreted asapplying a predefined fallback mode related UL-DL configuration to alinked valid duration.

For instance, the term ‘UL-DL configuration successfully detected perindividual cell’ indicates UL-DL configurations detected if radioresource usage (re)configuration message (UL-DL reconfiguration DCI)related CRC check is true. On the other hand, the other term ‘validUL-DL configuration successfully detected per individual cell’ indicatesUL-DL configurations of not changing UL subframe on reference DL HARQtimeline related UL-DL configuration for DL usage or not changing DLsubframe on reference DL HARQ timeline related UL-DL configuration forUL usage as well as UL-DL configurations detected if radio resourceusage (re)configuration message (UL-DL reconfiguration DCI) related CRCcheck is true.

Moreover, per-cell fallback mode related UL-DL configuration may bedefined as: i) UL-DL configuration on SIB; ii) reference DL HARQtimeline related UL-DL configuration; iii) reference UL HARQ timelinerelated UL-DL configuration; or iv) UL-DL configuration applied to radioframe(s) {(m−1)·T/10, (m−1)·T/10+1, . . . , m·T/10−1}.

2-4. Fourth Method

A user equipment (hereinafter called eIMTA UE) set to monitor amultitude of radio resource usage (re)configuration messages (UL-DLreconfiguration DCI) on a multitude of subframes (indicated by bitmap)on radio frame(s) {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} can be set todecode only a previously defined (or signaled) number of radio resourceusage (re)configuration messages among a multitude of the radio resourceusage (re)configuration messages (UL-DL reconfiguration DCI) and thenapply a predefined fallback mode related UL-DL configuration to a linkedvalid duration: i) if there are at least two types of the UL-DLconfigurations most successfully detected per individual cell; or ii)there are at least two types of the valid UL-DL configurations.

Alternatively, the user equipment (hereinafter called eIMTA UE) can beset to decode a multitude of the radio resource usage (re)configurationmessages (UL-DL reconfiguration DCI) all and then apply a predefinedfallback mode related UL-DL configuration to a linked valid duration: i)if there are at least two types of the UL-DL configurations mostsuccessfully detected per individual cell; or ii) there are at least twotypes of the valid UL-DL configurations.

For instance, assume that a specific user equipment (e.g., Non-CA eIMTAUE) is set to monitor radio resource usage (re)configuration message(UL-DL reconfiguration DCI) on 8 subframes (indicated by bitmap) ofradio frame(s) {0, 1}. As a result from decoding the corresponding 8radio resource usage (re)configuration message (UL-DL reconfigurationDCI), assume that three valid UL-DL configuration #2 and two valid UL-DLconfiguration #5 are successfully detected (i.e., a case that there aretwo types of the valid UL-DL configurations detected most successfully).In this case, the corresponding user equipment applies predefinedfallback mode related UL-DL configuration to a linked valid durationaccording to the fourth method.

Moreover, according to the present method, the term ‘UL-DL configurationsuccessfully detected per individual cell’ indicates UL-DLconfigurations detected if radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI) related CRC check is true. On theother hand, the other term ‘valid UL-DL configuration successfullydetected per individual cell’ indicates UL-DL configurations of notchanging UL subframe on reference DL HARQ timeline related UL-DLconfiguration for DL usage or not changing DL subframe on reference DLHARQ timeline related UL-DL configuration for UL usage as well as UL-DLconfigurations detected if radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI) related CRC check is true.

Moreover, per-cell fallback mode related UL-DL configuration may bedefined as: i) UL-DL configuration on SIB; ii) reference DL HARQtimeline related UL-DL configuration; iii) reference UL HARQ timelinerelated UL-DL configuration; or iv) UL-DL configuration applied to radioframe(s) {(m−1)·T/10, (m−1)·T/10+1, . . . , m·T/10−1}.

2-5. Fifth Method

A user equipment (hereinafter called eIMTA UE) set to monitor amultitude of radio resource usage (re)configuration messages (UL-DLreconfiguration DCI) on a multitude of subframes (indicated by bitmap)on radio frame(s) {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} can be set todecode only a previously defined (or signaled) number of radio resourceusage (re)configuration messages among a multitude of the radio resourceusage (re)configuration messages (UL-DL reconfiguration DCI) and thenapply a predefined fallback mode related UL-DL configuration to a linkedvalid duration if at least one ‘invalid UL-DL configuration’ exists in‘UL-DL configurations most successfully detected’ per individual cell.Alternatively, the user equipment (hereinafter called eIMTA UE) can beset to decode a multitude of the radio resource usage (re)configurationmessages (UL-DL reconfiguration DCI) all and then apply a predefinedfallback mode related UL-DL configuration to a linked valid duration ifat least one ‘invalid UL-DL configuration’ exists in ‘UL-DLconfigurations most successfully detected’ per individual cell.

In this case,

the term ‘UL-DL configuration successfully detected per individual cell’indicates UL-DL configurations detected if radio resource usage(re)configuration message (UL-DL reconfiguration DCI) related CRC checkis true.

And, the term ‘per-cell invalid UL-DL configuration’ indicates one of:i) UL-DL configuration of changing UL subframe on reference DL HARQtimeline related UL-DL configuration for DL usage; and ii) UL-DLconfiguration of changing DL subframe on reference DL HARQ timelinerelated UL-DL configuration for UL usage, despite being detected ifradio resource usage (re)configuration message (UL-DL reconfigurationDCI) related CRC check is true.

Moreover, per-cell fallback mode related UL-DL configuration may bedefined as: i) UL-DL configuration on SIB; ii) reference DL HARQtimeline related UL-DL configuration; iii) reference UL HARQ timelinerelated UL-DL configuration; or iv) UL-DL configuration applied to radioframe(s) {(m−1)·T/10, (m−1)·T/10+1, . . . , m·T/10−1}.

2-6. Sixth Method

According to the present method, on one radio resource usage(re)configuration message (UL-DL reconfiguration DCI) corresponding toUE-group common DCI, a multitude of indicators (e.g., one indicatorconfigured with 3 bits) can be transmitted/configured (cf. ‘1-1.Configuration of radio resource usage (re)configuration message’ and‘1-2. Transmission/reception and application of radio resource usage(re)configuration message (UL-DL reconfiguration DCI)’) in order foruser equipments, which use a multitude of eIMTA mode enabled cells forradio resource usage, or user equipments, which receive cooperativecommunication (CoMP) service from the eIMTA mode enabled cells for theradio resource usage, to receive UL-DL configuration information relatedto a multitude of the corresponding cells at a time.

In particular, a specific user equipment can obtain UL-DLreconfiguration information related to a multitude of cells related tocommunication of its own at a time through: i) indicator fields at somespecific location (e.g., a value equal to or smaller than M) previouslysignaled to a user equipment by a base station; or ii) indicator fieldsat some specific location derived on the basis of predefined rules,among total M indicator fields defined on one radio resource usage(re)configuration message (UL-DL reconfiguration DCI). In this case, thecorresponding one radio resource usage (re)configuration message (UL-DLreconfiguration DCI) can be transmitted on PDCCH common search space(CSS) of PCell.

Hence, considering such an operation, ‘UL-DL configurations detectedsuccessfully per individual cell’, which is described in the at leastone or more methods (i.e., some or all of the methods) (e.g., firstmethod, second method, third method, fourth method, and fifth method),can be interpreted as or limited to UL-DL configuration informationsreceived from indicator fields at (some) specific location designated tobe actually monitored/received by a specific user equipment among totalM indicator fields defined on one radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI). And, ‘valid UL-DL configurationsdetected successfully per individual cell’ can be interpreted as orlimited to valid UL-DL configuration informations received fromindicator fields at (some) specific location designated to be actuallymonitored/received by a specific user equipment among total M indicatorfields defined on one radio resource usage (re)configuration message(UL-DL reconfiguration DCI).

The case of applying such interpretation/restriction to the third methodis described as follows. First of all, a user equipment (eIMTA UE) setto monitor a multitude of radio resource usage (re)configurationmessages (UL-DL reconfiguration DCI) on a multitude of subframes(indicated by bitmap) of radio frame(s) {m·T/10, m·T/10+1, . . . ,(m+1)·T/10−1} can decode only a previously defined (or signaled) numberof radio resource usage (re)configuration messages among a multitude ofthe radio resource usage (re)configuration messages (UL-DLreconfiguration DCI) or all of a multitude of the radio resource usage(re)configuration messages (UL-DL reconfiguration DCI).

In this case, i) if ‘UL-DL configurations successfully detected’ or‘valid UL-DL configurations successfully detected’ from specificindicator field locations for the actual monitoring/receiving usagerelated to the corresponding UE (eIMTA UE) on the correspondingindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI) are not the same all, it is able to re-interpretthat a predefined fallback mode related UL-DL configuration is appliedto a linked valid duration (e.g., case of Non CA of eIMTA-Enable Cells).Alternatively, ii) if ‘UL-DL configurations successfully detected’ or‘valid UL-DL configurations successfully detected’ from specificindividual indicator field locations for the actual monitoring/receivingusage related to the (corresponding) UE (eIMTA UE) on the correspondingindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI) are not the same all, it is able to re-interpretthat a predefined fallback mode related UL-DL configuration on a celllinked to the indicator field location is applied to a linked validduration (e.g., case of CA of eIMTA-Enable Cells).

Additionally, in this case, if UL-DL configuration informations received(or successfully detected) from indicator fields at some specificlocation designated to be actually monitored/received by the(corresponding) UE (eIMTA UE) on the individual radio resource usage(re)configuration message (UL-DL reconfiguration DCI) are the same allbut UL-DL configuration informations received (or successfully detected)from indicator fields at different location (e.g., indicator fieldslinked to another user equipment belonging to the same UE group) are notthe same all, the (corresponding) UE (eIMTA UE) regards that all thesame ‘successfully detected UL-DL configurations’ are received on theindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI).

Alternatively, if valid UL-DL configurations received (or successfullydetected) from indicator fields at some specific location designated tobe actually monitored/received by the corresponding UE (eIMTA UE) on theindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI) are the same all but valid UL-DL configurationsreceived (or successfully detected) from indicator fields at differentlocation (e.g., indicator fields linked to another user equipmentbelonging to the same UE group) are not the same all, the correspondingUE (eIMTA UE) regards that all the same ‘successfully detected validUL-DL configurations’ are received on the individual radio resourceusage (re)configuration message (UL-DL reconfiguration DCI).

In this case, the present example implicitly means that reconfigurationperiodicity of UEs sharing the same eIMTA-RNTI (cf. ‘1-1. Configurationof radio resource usage (re)configuration message’ and ‘1-2.Transmission/reception and application of radio resource usage(re)configuration message’) or UEs belonging to the same UE group may bedifferent.

On the other hand, for another example, ‘UL-DL configurations detectedsuccessfully per individual cell’, which is described in the at leastone or more methods (i.e., some or all of the methods) (e.g., firstmethod, second method, third method, and fourth method), can beinterpreted/defined as all UL-DL configuration informations receivedthrough total M indicator fields defined on one radio resource usage(re)configuration message (UL-DL reconfiguration DCI). And, ‘valid UL-DLconfigurations detected successfully per individual cell’ can beinterpreted/defined as all valid UL-DL configuration informationsreceived through total M indicator fields defined on one radio resourceusage (re)configuration message (UL-DL reconfiguration DCI).

If such interpretation is applied to the third method, a user equipment(eIMTA UE) set to monitor a multitude of radio resource usage(re)configuration messages (UL-DL reconfiguration DCI) on a multitude ofsubframes (indicated by bitmap) of radio {m·T/10, m·T/10+1, . . . ,(m+1)·T/10−1} frame(s) {m·T/10, m·T/10+1, . . . , (m+1)·T/10−1} decodesonly a previously defined (or signaled) number of radio resource usage(re)configuration messages (UL-DL reconfiguration DCI) among a multitudeof the radio resource usage (re)configuration messages (UL-DLreconfiguration DCI) or all of a multitude of the radio resource usage(re)configuration messages (UL-DL reconfiguration DCI). Thereafter, if‘UL-DL configurations successfully detected’ or ‘valid UL-DLconfigurations successfully detected’ from all indicator field locationsincluding specific indicator field locations for the actualmonitoring/receiving usage related to the corresponding UE (eIMTA UE) onthe corresponding individual radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI) are not the same all, it is able tore-interpret that a predefined fallback mode related UL-DL configurationis applied to a linked valid duration.

Additionally, in this case, if UL-DL configuration informations received(or successfully detected) from indicator fields at some specificlocation designated to be actually monitored/received by the(corresponding) UE (eIMTA UE) on the individual radio resource usage(re)configuration message (UL-DL reconfiguration DCI) are the same allbut UL-DL configuration informations received (or successfully detected)from indicator fields at different location (e.g., indicator fieldslinked to another user equipment belonging to the same UE group) are notthe same all, the (corresponding) UE (eIMTA UE) regards that all thesame ‘successfully detected UL-DL configurations’ are received on theindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI). Alternatively, if valid UL-DL configurationsreceived (or successfully detected) from indicator fields at somespecific location designated to be actually monitored/received by thecorresponding UE (eIMTA UE) on the individual radio resource usage(re)configuration message (UL-DL reconfiguration DCI) are the same allbut valid UL-DL configurations received (or successfully detected) fromindicator fields at different location (e.g., indicator fields linked toanother user equipment belonging to the same UE group) are not the sameall, the corresponding UE (eIMTA UE) regards that all the same‘successfully detected valid UL-DL configurations’ are received on theindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI).

In this case, the present example implicitly means that reconfigurationperiodicity of UEs sharing the same eIMTA-RNTI (cf. ‘1-1. Configurationof radio resource usage (re)configuration message’ and ‘1-2.Transmission/reception and application of radio resource usage(re)configuration message’) or UEs belonging to the same UE group is thesame.

2-7. Seventh Method

For instance, on one radio resource usage (re)configuration message(UL-DL reconfiguration DCI) corresponding to UE-group common DCI, amultitude of indicators (e.g., one indicator configured with 3 bits) canbe transmitted (or configured) (cf. ‘1-1. Configuration of radioresource usage (re)configuration message’ and ‘1-2.Transmission/reception and application of radio resource usage(re)configuration message (UL-DL reconfiguration DCI)’) in order foruser equipments, which use a multitude of eIMTA mode enabled cells forradio resource usage, or user equipments, which receive cooperativecommunication (CoMP) service from the eIMTA mode enabled cells for theradio resource usage, to receive UL-DL configuration information relatedto a multitude of the corresponding cells at a time.

In particular, a specific user equipment can obtain UL-DLreconfiguration information related to a multitude of cells related tocommunication of its own at a time through indicator fields at somespecific location (e.g., a value equal to or smaller than M) previouslysignaled to a user equipment by a base station (or, through indicatorfields at some specific location derived on the basis of predefinedrules) among total M indicator fields defined on one radio resourceusage (re)configuration message (UL-DL reconfiguration DCI). In thiscase, the corresponding one radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI) can be transmitted on PDCCH commonsearch space (CSS) of PCell.

Considering such an operation, reception information of a specific userequipment in the at least one or more methods (i.e., some or all of themethods) (e.g., first method, second method, third method, fourthmethod, and fifth method) can be defined as ‘information received onlyfrom indicator fields at some specific location designated to beactually monitored/received by the specific user equipment among total Mindicator fields defined on radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI) at a multitude of radio resourceusage (re)configuration message (UL-DL reconfiguration DCI) monitoringtiming points’ or ‘information received through total M indicator fieldsdefined on radio resource usage (re)configuration message (UL-DLreconfiguration DCI) at a multitude of radio resource usage(re)configuration message (UL-DL reconfiguration DCI) monitoring timingpoints’.

In this case, when the definition as ‘information received only fromindicator fields at some specific location designated to be actuallymonitored/received by the specific user equipment among total Mindicator fields defined on radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI) at a multitude of radio resourceusage (re)configuration message (UL-DL reconfiguration DCI) monitoringtiming points’ is applied to the third method, if UL-DL configurationinformations received from indicator fields at some specific locationdesignated to be actually monitored/received by the UE (eIMTA UE) on theindividual radio resource usage (re)configuration message (UL-DLreconfiguration DCI) are the same all but UL-DL configurationinformations received from indicator fields at different location (e.g.,indicator fields linked to another user equipment belonging to the sameUE group) are not the same in part at least (i.e., all or some), thecorresponding UE (eIMTA UE) regards that all the same informations arereceived on the individual radio resource usage (re)configurationmessage (UL-DL reconfiguration DCI). In this case, suchmethod/interpretation implicitly means that reconfiguration periodicityof UEs sharing the same eIMTA-RNTI (cf. ‘1-1. Configuration of radioresource usage (re)configuration message’ and ‘1-2.Transmission/reception and application of radio resource usage(re)configuration message’) (or UEs belonging to the same UE group) maybe different.

Moreover, for example, when the method/interpretation defined as‘information received through total M indicator fields defined on radioresource usage (re)configuration message (UL-DL reconfiguration DCI) ata multitude of radio resource usage (re)configuration message (UL-DLreconfiguration DCI) monitoring timing points’ is applied to the thirdmethod, if UL-DL configuration informations received from indicatorfields at some specific location designated to be actuallymonitored/received by the UE (eIMTA UE) on the individual radio resourceusage (re)configuration message (UL-DL reconfiguration DCI) are the sameall but UL-DL configuration informations received from indicator fieldsat different location (e.g., indicator fields linked to another userequipment belonging to the same UE group) are not the same in part atleast (i.e., all or some), the corresponding UE (eIMTA UE) regards thatdifferent informations are received on the individual radio resourceusage (re)configuration message (UL-DL reconfiguration DCI). In thiscase, such method/interpretation implicitly means that reconfigurationperiodicity of UEs sharing the same eIMTA-RNTI (cf. ‘1-1. Configurationof radio resource usage (re)configuration message’ and ‘1-2.Transmission/reception and application of radio resource usage(re)configuration message’) (or UEs belonging to the same UE group) isthe same.

At least one (i.e., some or all) of the first to seventh methodsdescribed in the present invention may be set to apply only to somepredefined cases limitedly. For instance, the embodiments of the presentinvention may be set to be limitedly apply to: i) specific systemenvironment (e.g., FDD system, TDD system); ii) RRC-CONNECTED or IDLEmode of UE only; iii) case that dynamic change (eIMTA) mode for radioresource usage is enabled; or iv) specific eIMTA-enabled componentcarrier (CC) or specific eIMTA-enabled cell (e.g., PCell, SCell) incomponent aggregation (CA) applied environment only.

Since the embodiments described in the methods of the present inventioncan be included as one of methods for implementing the present inventionas well, it is apparent that such embodiments can be regarded as a sortof independent methods. Although the aforementioned methods of thepresent invention can be implemented independently, at least one or moreembodiments of the present invention can be implemented in a manner ofbeing combined/merged in part or entirely.

Moreover, information on the aforementioned rules/configurations/methodsof the present invention, information on whether to apply thecorresponding rules/configurations/methods and the like can be notifiedto a user equipment by a base station through predefined signal (e.g.,physical layer signal, upper layer signal).

FIG. 13 shows one example of a base station and a user equipmentapplicable to one embodiment of the present invention.

If a relay is included in a wireless communication system, acommunication in backhaul link is performed between a base station and arelay. And, a communication in access link is performed between a relayand a user equipment. Hence, the base station or user equipment shown inthe drawing may be substituted with a relay in some cases.

Referring to FIG. 13, a wireless communication system includes a basestation (BS) 110 and a user equipment (UE) 120. The BS 110 includes aprocessor 112, a memory 114, and a Radio Frequency (RF) unit 116. Theprocessor 112 may be configured to perform the proposed proceduresand/or methods according to the present invention. The memory 114 isconnected to the processor 112 and stores various types of informationsrelated to operations of the processor 112. The RF unit 116 is connectedto the processor 112 and transmits and/or receives radio signals. The UE120 includes a processor 122, a memory 124, and an RF unit 126. Theprocessor 122 may be configured to perform the proposed proceduresand/or methods according to the present invention. The memory 124 isconnected to the processor 122 and stores various information related tooperations of the processor 122. The RF unit 126 is connected to theprocessor 122 and transmits and/or receives radio signals. The BS 110and/or the UE 120 may include a single antenna or multiple antennas.

The embodiments of the present invention described above arecombinations of elements and features of the present invention in apredetermined form. The elements or features may be considered selectiveunless otherwise mentioned. Each element or feature may be practicedwithout being combined with other elements or features. Further, anembodiment of the present invention may be constructed by combiningparts of the elements and/or features. Operation orders described inembodiments of the present invention may be rearranged. Someconstructions of any one embodiment may be included in anotherembodiment and may be replaced with corresponding constructions ofanother embodiment. It is obvious to those skilled in the art thatclaims that are not explicitly cited in each other in the appendedclaims may be presented in combination as an embodiment of the presentinvention or included as a new claim by a subsequent amendment after theapplication is filed.

In this disclosure, a specific operation explained as performed by abase station may be performed by an upper node of the base station insome cases. In particular, in a network constructed with a plurality ofnetwork nodes including a base station, it is apparent that variousoperations performed for communication with a terminal can be performedby a base station or other networks except the base station. ‘Basestation (BS)’ may be substituted with such a terminology as a fixedstation, a Node B, an eNode B (eNB), an access point (AP) and the like.

The embodiments of the present invention may be achieved by variousmeans, for example, hardware, firmware, software, or a combinationthereof. In a hardware configuration, the methods according to exemplaryembodiments of the present invention may be achieved by one or moreapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In a firmware or software configuration, an embodiment of the presentinvention may be implemented in the form of a module, a procedure, afunction, etc. Software code may be stored in a memory unit and executedby a processor.

The memory unit is located at the interior or exterior of the processorand may transmit and receive data to and from the processor via variousknown means.

Those skilled in the art will appreciate that the present invention maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent invention. The above embodiments are therefore to be construedin all aspects as illustrative and not restrictive. The scope of theinvention should be determined by the appended claims and their legalequivalents, not by the above description, and all changes coming withinthe meaning and equivalency range of the appended claims are intended tobe embraced therein.

INDUSTRIAL APPLICABILITY

Although a method of transceiving a signal in a wireless communicationsystem and apparatus therefor are described mainly with reference toexamples applied to 3GPP LTE system, as mentioned in the foregoingdescription, the present invention is applicable to various kinds ofwireless communication systems as well as to the 3GPP LTE system.

What is claimed is:
 1. A method of transmitting and receiving a signalin a user equipment of a wireless communication system supportive ofreconfiguration of radio resource, comprising: monitoring a radioresource reconfiguration control information on a multitude of subframesin monitoring periodicity set for radio resource reconfiguration,wherein a first UL-DL configuration according to the radio resourcereconfiguration control information is valid only if detected equallyfrom a multitude of the subframes and wherein a multitude of thesubframes comprise subframes configured to being monitored the radioresource reconfiguration control information of the user equipment. 2.The method of claim 1, further comprising: if the first UL-DLconfiguration is not valid, performing fallback for transceiving thesignal with a base station according to a second UL-DL configuration onSIB (system information block).
 3. The method of claim 1, furthercomprising: if the first UL-DL configuration is valid, transceiving thesignal with the base station on a time interval having the first UL-DLconfiguration applied thereto.
 4. The method of claim 1, wherein theradio resource reconfiguration information is transmitted through commonsearch space (CSS) on physical downlink control channel (PDCCH).
 5. Themethod of claim 4, wherein the first UL-DL configuration is indicatedusing an indicator included in the radio resource reconfigurationcontrol information.
 6. The method of claim 4, wherein the radioresource reconfiguration control information comprises a multitude ofindicators and wherein the first UL-DL configuration is indicatedaccording to an indicator corresponding to a field designated to bemonitored by the user equipment among a multitude of the indicators. 7.The method of claim 1, wherein a multitude of the subframes areindicated by an upper layer.
 8. In transceiving a signal in a wirelesscommunication system supportive of reconfiguration of radio resource, auser equipment comprising: a radio frequency unit; and a processorconfigured to monitor a radio resource reconfiguration controlinformation on a multitude of subframes in monitoring periodicity setfor radio resource reconfiguration, wherein a first UL-DL configurationaccording to the radio resource reconfiguration control information isvalid only if detected equally from a multitude of the subframes andwherein a multitude of the subframes comprise subframes configured tobeing monitored the radio resource reconfiguration control informationof the user equipment.
 9. The user equipment of claim 8, wherein if thefirst UL-DL configuration is not valid, the processor is furtherconfigured to perform fallback for transceiving the signal with a basestation according to a second UL-DL configuration on SIB (systeminformation block).
 10. The user equipment of claim 8, wherein if thefirst UL-DL configuration is valid, the processor is further configuredto transceive the signal with the base station on a time interval havingthe first UL-DL configuration applied thereto.
 11. The user equipment ofclaim 8, wherein the radio resource reconfiguration information istransmitted through common search space (CSS) on downlink controlchannel (physical downlink control channel (PDCCH)).
 12. The userequipment of claim 11, wherein the first UL-DL configuration isindicated using an indicator included in the radio resourcereconfiguration control information.
 13. The user equipment of claim 11,wherein the radio resource reconfiguration control information comprisesa multitude of indicators and wherein the first UL-DL configuration isindicated according to an indicator corresponding to a field designatedto be monitored by the user equipment among a multitude of theindicators.
 14. The user equipment of claim 8, wherein a multitude ofthe subframes are indicated by an upper layer.